Carton



Oct. 30, 1956 A. J. WEISS 2,768,776v

CARTON Filed Dec. 2, i952 2 Sheets-Sheet 1 m J {0 J9 {5 3 f 7 i A l4 i Q 1/ u 11 14 J y I INVENTOR. l ARTHUR .7." WEISS Arramveys A. J. WEISS Oct. 30, 1956 CARTON 2 Sheets-Sheet 2 Filed Dec. 2, 1952 INVENTOR. ARTHUR J. Mass ATTORNEKS CARTON Arthur J. Weiss, West Englewood, N. J., assignor to Robert Gair Company, Inc., New York, N. Y., a corporation of Delaware Application December 2, 1952, Serial No. 323,630

2 Claims. (Cl. 229-31) The invention relates to folding cartons of paperboard and the like, and more particularly to cartons of tray form and of the type which is generally known in the business as a simplex carton. This type of carton has corner sections infolding along diagonal fold lines and end flaps folding inwardly over the infolding corner sections. The diagonal fold lines of the corner sections define triangular glue lap areas which are adhesively secured to the end walls of the carton. Such cartons are widely used in boxing flat articles such as shirts, and are favored because of the rapidity and ease with which they can be erected for use, starting with the carton in its fiat folded form as shipped to the user by the carton manufacturer.

Many practical problems have been encountered in the manufacture of this type of carton. One of the more serious ones has been how to obtain satisfactory adherence over the triangular glue lap areas. In setting up the cartons there is quite a pull on the glue flaps, so good adherence is needed. However, good adherence is hard to obtain in practice. One reason this is so, is that usual production methods call for feeding the flat folded cartons through pressure roller devices following application of the glue or other adhesive to the glue laps. Ordinarily these pressure devices extend over the entire length of the folded carton, and since the side walls of the carton are usually of double thickness whereas the corner sections are of a single thickness, pressure exerted by the rollers is uneven and is least effective where needed most, i. e. over the triangular glue lap areas. Attempts to overcome this condition have not been very successful. One idea that has been tried out heretofore was to make a slit in the corner section extending from the diagonal fold line through the unglued part of the corner section to get a slight enlargement of the adhesive area between the lap and the end wall. This, however, was found to result in a weakened corner which would tear too easily, and probably cause more trouble than it cured. So the original problem remained without any really satisfactory solution being apparent. The thing that started me thinking about a different kind of solution was the discovery of the cause for the poor adherence at the glue lap and the realization that if I could only find a way to get better pressure over the glue lap areas this might be better than anything that had been tried before.

The final answer which I discovered was to extend the corner sections out over the inwardly folding end flaps and to secure these extended portions to the end flaps.

I found that this not only made it possible to get better gluing pressure, but further improved the glued joint by providing increased gluing area. Further, I discovered that this construction assists in the erection of the side walls when pressure is applied in the usual manner at the ends of the blank at the time the carton is being set up.

Another advantage which I found to accrue from my carton construction is that the carton is easier to set up. This result I attribute to a sort of pushing action produced by the corner section extensions. The end flaps crowd nited States Patent "ice the extensions at the fold lines at the tops of the end walls, and this has a tendency to force the side walls to snap upwardly toward their erected position. Furthermore, the construction gives additional columnar strength to the corners of the erected carton as set up for use.

In the drawings, wherein I have illustrated what I now consider to be the best form of my invention:

Fig. 1 is a face view of a blank from which the carton is formed. The view faces what will become the inner bottom of the carton.

Fig. 2 illustrates the result of the first folding step in making a carton from the blank of Fig. 1, only the upper right hand portion of the structure being shown.

Fig. 3 is a view similar to Fig. 2, and illustrates the result of the second folding step.

Fig. 4 is a top plan view of the completed carton in fiat folded form and following a third folding step. This is the form in which the carton passes between the pressure rollers or other pressure elements used in the gluing operation.

The cross-hatched portion of Fig. 5 is an enlarged fragmentary section taken as indicated at 5-5 in Fig. 4, and the view as a whole represents a corner of the fiat folded blank passing between the rollers of the gluing machine.

Fig. 6 is a longitudinal cross-sectional view taken in the general plane indicated at 6-6 in Fig. 4, but showing the carton partially erected.

Fig. 7 is a view similar to Fig. 6, but showing the carton fully erected.

Fig. 8 is a perspective view of the fully erected carton ready for use.

In the type of carton to which my invention is applicable, there is a bottom panel 9, side walls 10 and end walls 11 extending from the edges of the bottom panel at fold lines 12 and 13. The side and end walls have inwardly folding flaps 14 and 15, respectively, adjoining such walls along fold lines 16 and 17. Corner sections 18 adjoin the ends of the side and end walls along fold lines 19 and 20. Diagonal fold lines 21 in the corner sections extend from the respective corners of the bottom panel, defining in each corner section a triangular glue lap 22 for adhesive attachment to the respective end walls. According to my invention there is employed in this carton construction an extension 23 adjoining glue lap 22 of each corner section 18 along a fold line 24 substantially in line with fold line 17. Extensions 23 are adhesively secured to flaps 15.

In my preferred construction, the inwardly folding side Wall flaps 14 have corner tabs 25 overlying a portion of the respective corner sections outside of the defined triangular glue lap areas. The inwardly folding end flaps and the corner section extensions 23 provide means for building up the thickness of the folded carton stock during gluing to secure effective pressure over the triangular glue laps 22 adjacent corner tabs 25. Also in my preferred construction the corner section extensions 23 terminate short of the corner tabs when the carton is in its fiat folded position, or the extensions are notched out as at 26 to equalize the thickness of the folded carton stock adjacent glue laps 22. See Figs. 1, 4 and 5.

In producing the flat folded carton from the blank of Fig. 1, glue is first applied to glue laps 22 and extensions 23 over the areas indicated by the stipling in Fig. 1. Glue may also be applied as desired to side wall flaps 14. Next the flaps 14 are folded inwardly as shown in Fig. 2, and then the side walls 10 are folded as shown in Fig. 3. Finally the end wall flaps 15 are folded as shown in Fig. 4 and the flat folded carton is then subjected to sealing pressure as by passing it between pressure rollers 27 (Fig. 5) or between pressure elements comprising opposed belts each supported on a series of pressure rollers.

Such pressure sealing means ordinarily are arranged on the gluing machine between the gluing and folding mechanism and the tying table at the end of the machine where the flat folded cartons are collected and tied into bundles.

The terms and expressions which I have employed are used in a descriptive and not a limiting sense, and I have no intention of excluding such equivalents of the invention described, or of portions thereof, as fall within the purview of the claims.

I claim:

1. A folding carton having a bottom panel, side walls and end walls extending from the edges of the bottom panel, said side walls and end walls having inwardly folding flaps adjoining said side walls and end walls along fold lines which when the carton is erected for use define the upper edges of the respective side and end walls, corner sections adjoining the ends of the side and end walls along fold lines, diagonal fold lines in said corner sections extending from the respective corners of the bottom panel, said lines defining in each corner section a triangular glue lap for adhesive attachment to the respective end walls, and each corner section having an extension adjoining its triangular glue lap along a fold line substantially in line with the fold line which defines the upper edge of the respective end wall, said extensions being initially free of connection to the inwardly folding end wall flaps and being adhesively secured to the respective inwardly folding end wall flaps while the latter are folded flat against the end walls whereby said extensions are fixed to the respective inwardly folding end flaps in an olfset relationship which creates resistance to unfolding of the folded end flaps, the inwardly folding side wall flaps having corner tabs overlying a portion of the respective corner sections outside of the defined triangular glue lap areas, and said corner section extensions terminating short of said corner tabs when the carton is in its fiat folded form with the side walls and flaps inwardly folded and the end wall flaps folded against the end walls.

2. A folding carton having a bottom panel, side walls and end walls extending from the edges of the bottom panel, said side Walls and end walls having inwardly folding flaps adjoining said side walls and end walls along fold lines which when the carton is erected for use define the upper edges of the respective side and end walls, corner sections adjoining the ends of the side and end walls along fold lines, diagonal fold lines in said corner sections extending from the respective corners of the bottom panel, said lines defining in each corner section a triangular glue lap for adhesive attachment to the respective end walls, and each corner section having an extension adjoining its triangular glue lap along a fold line substantially in line with the fold line which defines the upper edge of the respective end wall, said extensions being initially free of connection to the inwardly folding end wall flaps and being adhesively secured to the respective inwardly folding end wall flaps while the latter are folded flat against the end walls whereby said extensions are fixed to the respective inwardly folding end flaps in an offset relationship which creates resistance to unfolding of the folded end flaps, the inwardly folding side wall flaps having corner tabs overlying a portion of the respective corner sections outside of the defined triangular glue lap areas, and said corner section extensions being notched out where they lie opposite said corner tabs when the carton is in its flat folded form with the side wall flaps folded over and glued to the side walls, the side walls folded inwardly and the end wall flaps folded against the end walls.

References Cited in the file of this patent UNITED STATES PATENTS 1,354,012 Bachmann Sept. 28, 1920 2,038,217 Rosenthal Apr. 21, 1936 2,217,504 Bergstein Oct. 8, 1940 2,233,874 Rosenthal Mar. 4, 1941 2,326,281 Becker Aug. 10, 1943 2,334,425 Lowey Nov. 16, 1943 2,377,125 Borah et a1. May 29, 1945 2,681,173 Guyer June 15, 1954 

